Piston ring



PISTON RING Fil d sebb. 2, 1922 2; 22 1 lime/72 v)" g E r liar lla/M012 Patented Feb. 24, 1925.

HARRY o. l mitson; or sit. FAULQIVIINNESOTA.

: PISTON RING.

Application filed September To all whom itmay concern:

Beit known that LVHARRY GuHaNso-n, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented, certain new and J J useful Improvements in Piston Rings, of

which thefollowing 1s a specification.

jointless piston ring, which v Will function This invention relates to piston packing rings for internal combustion engines, and has for its ob ec t to provide a one piece,

singly, with improved efficiency, as a suhsti tute for the piston rings ordinar ly employed at the top of the piston, n 1y improved ring having approximately the samepircumfer- '7 ential effective packing length, Without any,

intermediate lap joints, g

A further object of the invention, is the provision of a unitarypistonring having a slidingsurtace, which is' approximately equal to the aggregate sliding surface, of the upper piston rings ordinarily employed, but which may he inserted in the piston ring grooves Without detaching the pistons from the connecting rods, and which will slidaloly engage, under its own spring stress, the tvall of ordinary split ringspand inany of those employing auxiliary spring rings v for hacking up the spht ring, to secure ample slde pressure. p A

Further, 'my n proved ring s cheap to manufacture, inview of the number of rings it displaces, and involves no coacting separate parts relied upon to slide upon one an other to be effective. I

Other objects ofthe invention vv ll be pointedhout as this specification progresses,

In the accompanying drawings: c Figure 1, is a sideelevation of my iniproved p acking ring. a g

' Figure 2 is ,a. top :viewgof "Same; shovying it applied to the-piston, the latter being partly broken ayvay. 1 a p Figure 3, is a fragmentary elevation of the cylinder and piston, showing theheli; cal packing ring groove. v

Figure 4, is a perspective view-of the piston top plate or cap, forming part of my invention. a H

Figure 5, is a perspectiveview of a fragment of the piston, showing the end of the piston grooveand; ring.

2, i922, semi No. 5851883.

1 F refi; sv a ,dias mmatw f tary side elevation partly section, 'and7draWn to a reduced scale, of a cylinder blockfshowing a piston therein, and illustrating the mode oi inserting the packing ring in the p ston groove; and

Figure 7, lsa side W b a'p'a -tt t upper coil of the piston" ring, showing-it trai-e ene e tv. My mp v d. ra k e ane -fil s enete i y the c erA; mpr e fia st p i shi b srr e. men l; i' c e i e l i' i e s s tion, and siaped to form a lielical ring or helix of prefer aiblyiour Icoils of uni form pitch and diameter, the upper end of the ring being formed to present a'gllat top sidedisposed in aiplane at"right 'angles to the axis ot'the helix, or, in other vvordspthe helical ring is cut off square atthe'top. The

upper extremity of the coiled -strip, isfpi'oviolecl with an inwardly extending, horizontally disposed lug or extension l, haiving a ma nl disposed slotted openings.

The piston '3, is formed ,vv itli 'anfexternal squai'e thread' l, having a pitch"equalto the pitch of the coils ofthe"pistonringfand being in extent atrffle lon ger thanis aidi ring to form a clearance ,5 at the l oweffextiiemity of the" latter, l'vvhen the square, fend-10f" the ring is flush vvith' the top T oflthe piston.

The clearance inentioned'p W niits the piston ring to expand and" contract cirt;L1ii1'feren tially, responsive to alchange iii tinpei ature ofthe parts, motor, as when running-"at, jlo vv oi'iliigh speed. 'The under sideol thelug'or' extension 1, is loc' tedin-theplancpf the top 9f the piston ring, 'andrestspn the"top 6'"of the piston 3',when mounted ins tion. :The outside of ft'he' threjad 4 of the piston, is preferably e u al indiamterjtO the diameter ofthe rest o-fthe piston, which isusually a trifle"smaller 'th'an he hereof the cylinder.

The piston ring is originally niatle a trifle larger in diameter th'an'the ib'ore ofthe cylincler, as is plainly indicatedin Figuref3, wherein the p'ston is shoyvn ected into the cylinder, and the-piston ring 'is shown in its 'un'fiexed origiharstate.

, Secured to the top of the pistonfand being of same diameter, is thetop plate orfcapi..8, having central which loosely extends 'the cap screw 10, which -latter is threaded into the top fof the piston, as indicated in dotted'lines Figdue to the activities of the orking pbsiholt opening 19," through,

ure 8. The cap is preferably recessed cn trally in the under side, as at 11, order to secure a firm bearing around the outer edge thereof in connection with the piston. The cap is further provided with the elongated opening 12, located oii center, and adapted to receive a suitable screw 13, which latter is threaded in the opening 14 in the top of the piston, whereby, with the cap screw 10, the top plate may befirmly and non-rotatably secured to the top of the piston. The under side of the top plate is further formed with a recess 15, shaped to receive the lug 1 fiatwise, so that the under side of said lug will be flush with the under.

side of the top plate, the lug being slidably held in said recess by means of the countersunk screw 16, the slotted hole 2 being countersunk accordingly, and the hole for the screw extending through the top plate, and being in register with the tapped. hole 16 in the top of the piston.

The cap or top plate is further provided with shallow, circular recesses 17, one on either side of the center, said recesses being adapted to receive the studs 18 of the spanner wrench 19, whereby the cap may be rotated.

The recess 15, is properly located on the under side of the cap 8, to hold the piston ring A concentric therewith, the screw 16 being applied in a manner to permit the upper extremity of the piston ring to slide in the slotted opening 2, to thereby give it freedom of action to press against the wall of the cylinder.

As hereinbefore stated, the ring is no-r-' nially slightly larger in diameter than the bore of the cylinder, commonly termed oversize, and is placed on the piston by simply screwing the coiled strip from above downwards into the grooves 21, formed by the threads of the piston (as is diagrammatically indicated in Figure 6 of the drawings), until the ca 8 rests firmly on top of the piston, as s own in Figure 3, when the screws 10 and 13 are applied to firmly secure the cap. The packing ring is thus firmly anchored at its upper extremity (by means of the lug 1 in the recess 15) to the piston, while its lower free end 20 is located (Figure 5) adjacent to the clearing space 5. Obviously, with the application of heat, the packing ring will expand circumferentially, and being anchored at its upper extremity, the strip of which it is composed will elongate and be compelled to traverse the piston groove 21 downwardly during expansion, and thereby be projected into the clearance space 5. This longitudinal sliding movement of the ring strip varies constantly in extent, in direct proportion to the variation of temperature of the piston, which change in temperature is due to the changing oi speeds of the 'motor, whereby the relative position of the sliding surface of the ring, with respect to the bore of the cylinder, is constantly changing, thus inducing even wearing of the bore, and avoiding pitting of the latter. Further, by having a helical one piece ring, oil, ordinarily accumulating above or between the packing rings, will be conducted, or will work itself down the inclined coils of the ring to the clearance space 5, where it will be discharged.

As the ring is screwed into the piston groove, it is flexed to assume a smaller diameter, the outwardly directed stress thereby developed, pressing the ring firmly against the wall of the cylinder to serve as a packing. As the ring is a continuous helix, here shown constituting four (4) rings, the pressure, obviously, is uniform and is directed radially outwardly against the cylinder wall, as distinguished from ordinary split rings, where it becomes necessary to stagger the splits thereof, in order to secure more or less even outward pressure. As described, the under side of the top plate 8 forms a joint with the top surface 22, of the squared end of the packing ring. Since the latter is anchored to the top plate, this joint remains unmoved during expansion.

Referring to Figures 1 and 2, the pitch of the ring, as here shown, is such, that the width of the metal strip of which it is composed, is approximately two-thirds of the pitch, as shown at 23, and, therefore, the top surface 22 of the ring will extend twothirds of a revolution, from the line 24 to the line 25, at which latter point the groove of the piston bein at its full width. It will be observed that rom the lines 24 to 25, the clearance space 26 back of the ring, is ex-\ posed and opens upwardly. .The object of the top plate S, is to cover this opening and make the joint between the upper edge 22 and the under side of the top plate. Thus, I secure a leak proof joint at the juncture of the packing ring with the plate. It is to be understood, that the ring may be inserted, without the top plate being secured thereto, and the top plate later placed in osition, in which case the screw 13 need not be used, as the terminal of the packing ring will still be anchored in the recess 15.

While I have shown the plate like lug 1, to cover but part of the clearance 26, I can extend it to the point 25 (Figure 2) as indicated by the fine dotted lines 16", whereby I effectually seal said clearance space. When I thus extend'saidlug, the recess 15 is enlarged accordingly; or I reverse the screw 16 and thread it into the opening 16,

when the top plate may be dispensed with.

In either case, the top plate 8, or the lug 1, constitute a cover secured to the packing ring, for sealing the joint betweenthe latter and the piston at the top of the latter.

The helical ring may" be said tobe ex:

pandible longitudinally in the helical groove of the piston, from a fixed point located at the top of the packing rin I claim:

1. In a piston packing ring, the combination with a piston having a square screw thread in the periphery thereof; of a plate removably secured to the piston head, a metal helix engaging the screw thread to form a seal, and means for removably con necting the plate to the metal helix.

2. In a piston packing ring, the combination with a piston having an external square screw thread of uniform diameter, terminating in the plane of the top thereof; of a strip of fiat, springy metal, rectangular in cross section and curved fiatwise to slidingly fit in the space between said screw'threads and extend uniformly beyond the face of the threads and terminating flush with the top of the piston, a plate covering the'top of th piston and removably secured thereto, and a slidable connection between said plate and piston ring.

3. In a piston packing ring, the combination with a piston having a square screw thread in the periphery thereof; of a plate reinovably secured to the piston head and in contact therewith at its circumference and having a recess therein, a metal helix engaging the screw thread to form a seal, and means to removably connect the helix to the recess in the removable plate.

4:. In a piston packing ring, the combination with a piston having an external square screw thread terminating in the plane of the top thereof; of a helical packing ring larger in diameter than said piston and made of springy metal and shaped to be screwed into engagement with said thread, and be spaced from the bottom thereof, and terminate short of the end thereof, and be flush with thetop of the piston, and a plate secured to the top of the packing ring extending over the space separating the latter from the bottom of said thread to close said space and resting on the top of the ston, and adapted to be secured thereto.

In testimony whereof I affix my signature.

HARRY C. HANSON. 

